Mechanism for correcting any tendency for a moving web to deviate from a required path

ABSTRACT

Mechanism for correcting any tendency for a moving web such, for example, as a strip of material being wound onto, or unwound from a roller, or an endless belt to deviate from a required path. The mechanism includes a rotatable roller around the periphery of which the web passes so as to be in frictional contact therewith through a predetermined arc. The periphery of the roller is in part constituted by a plurality of angularly spaced bars which are slidable longitudinally in a direction parallel to the axis of the rotation of the roller. At opposite ends of the roller respectively are a pair of relatively fixed cams for ensuring that the bars take up a predetermined longitudinal position whilst they move through the arc in which they are in frictional contact with the web. Means is provided for sensing any deviation of the web from its required path as it approaches the roller and a second pair of cams at opposite ends of the roller respectively are movable by said means to displace the bars longitudinally by an amount determined by said means whilst the bars are moving through the arc in which they are not in contact with the web.

United States Patent 1191 Greeves July 3, 1973 Primary Examiner-Allen N.Knowles Attorney-John C. Holman, Herbert Cantor et al.

[75] Inventor: Thomas William Greeves, [5 7] ABSTRACT B'rmmgham EnglandMechanism for correcting any tendency for a moving [73] Assignee:Cadbury Limited, Birmingham, web such, for example, as a strip ofmaterial being England wound onto, or unwound from a roller, or anendless belt to deviate from a re uired path. The mechanism [22] Ffled'July 1972 includes a rotatable rollgr around the periphery of [21] Appl.No.: 271,653 which the web passes so as to be in frictional contacttherewith through a predetermined arc. The periphery of the roller is inpart constituted b a plurality of angu- [301 Foreign Apphcauon P riomyData larly spaced bars which are slidabl e longitudinally in a July 16,1971 Great Britam 33,502/71 direction parallel to the axis of therotation of the roller. At opposite ends of the roller respectively area [52] U.S. Cl. 226/19, 226/23 pair of relatively fixed cams forensuring that the bars [51] III. C] B65I1 25/26 take up a predeterminedlongitudinal position whflst [58] Field Of Search 226/19, 23, 22, 190,they move through the arc in which they are in fric 226/199 tionalcontact with the web. Means is provided for sens ing any deviation ofthe web from its required path as [56] References C'ted it approachesthe roller and a second pair of cams at UNITED STATES PATENTS oppositeends of the roller respectively are movable by 3,069,921 12/1962 Davis226/19 x said m n to displace the bars ng n lly y n 3,052,395 9/1962Scott 226/19 X amount determined by said means whilst the bars are3,095,131 1 63 Robe so et a 26/ 19 X moving through the arc in whichthey are not in contact 3,637,122 1/1972 Tokunage 226/19 i h h b2,752,151 6/1956 Levine 226/20 4 Claims, 4 Drawing Figures H 4 m 10 FT],l2 l3 n ]4 H A L l T l 1 9 XX t 1 g a a a a 197 e PATENTEDJUL 3 I975SHEET 2 [IF 2 'FIG.2

FIG.3

MECHANISM FOR CORRECTING ANY TENDENCY FOR A MOVING WEB TO DEVIATE FROM AREQUIRED PATH This invention relates to mechanism for correcting anytendency for a moving web such, for example, as a strip of materialbeing wound onto, or unwound from a roll, or an endless belt to deviatefrom a required path.

The object of the invention is to provide such mechanism in a simple andconvenient form.

Mechanism according to the invention comprises in combination arotatable roller around the periphery of which the web passes so as tobe in frictional contact therewith throughout a predetermined arc, theperiphery of said roller being in part constituted by a plurality ofangularly spaced bars which are slidable longitudinally in a directionparallel to the axis of rotation of the roller, relatively fixed cams atopposite ends of the roller respectively for ensuring that the bars takeup a predetermined longitudinal position whilst moving through the arcin which they are in frictional contact with the web, means for sensingany deviation of the web from its required path as it approaches saidroller, and further cams at opposite ends of the roller respectively,said further cams being movable by said means to displace the barslongitudinally by an amount determined by said means during theirmovement through The are in which they are not in contact with the web.

In the drawings,

FIG. 1 is a sectional end view of an example of the invention,

FIG. 2 is a section on the line AA of FIG. 1,

FIG. 3 is a section on the line BB of FIG. 1, and

FIG. 4 is an end view of the correcting mechanism with the rollerremoved.

Referring to the drawings, there is provided a rotatable roller which isjournalled within bearings 11 and around the periphery of which a web 12passes. In the illustrated example the web 12 is in frictional contactwith the periphery of the roller 10 throughout an arc subtendingapproximately 180, whilst the other approximately 180 arc of the rolleris free of the web. The periphery of the roller 10 is in partconstituted by a plurality of equi-angularly spaced bars 13 which arelongitudinally slidable in a direction parallel to the axis of rotationof the roller 10.

At opposite ends of the roller 10 respectively are a pair of relativelyfixed cams 14 which are arranged to make contact with the ends of thebars 13 and ensure that the bars take up a predetermined longitudinalsetting during their movement through the arc in which they are incontact with the web. Since in practice the bars 13 will deviate fromtheir predetermined position by only a small amount as will bedescribed, portions of the surfaces of the earns 14 are constituted bythe peripheries of rotatable rollers 14 at the point which will besubjected to maximum use.

There are also provided at opposite ends of the roller 10 respectively apair of movable cams 15 which are carried by a member 16 which ispivotally connected by a pair of parallel links 17 to the base 18carrying the bearings 11, so as to be movable transversely relative tothe direction of travel of the web 12. The member 16 carries a pair ofupstanding brackets 19 which are slotted to receive respectively theopposite marginal edges of the web 12.

The cams 15 are positioned to make contact with opposite ends of thebars 13 respectively as the bars 13 move through the arc in which theyare not in contact with the web 12.

In operation, any deviation of the web 12 laterally from itspredetermined path as it approaches the roller 10 will causedisplacement of the member 16 and therefore set the earns 15 to aposition to displace the bars 13 longitudinally from the position inwhich they have been set by an amount dependent upon the degree ofdeviation of the web. As a result these bars will be in a displacedposition when they first make contact with the web 12. As the bars movethrough The are in which they are in contact with the web, they will bereturned by the fixed earns 14 to the predetermined position therebyreturning the web laterally to its required path. As a result the webleaving the roller 10 should be accurately positioned.

In order to enable the degree of correction for a given deviation of theweb to be varied the brackets 19 are preferably adjustable in adirection at right angles to the member 16 and perpendicular to theplane of the paper as viewed in FIG. 4.

It will be appreciated that it is not necessary for the web 12 to be incontact with the roller 10 through an are as large as 180, since an arcof or even less will give sufficient time for the movement of the bars13 to correct any deviation of the web from its predetermined course.However, in order to maximise the friction between the web and the bars13 the contacting surfaces of the latter may be knurled or coated withan abrasive material.

I claim:

1. Mechanism for correcting any tendency for a moving web to deviatefrom a required path comprising in combination a rotatable roller aroundthe periphery of which the web passes so as to be in frictional contacttherewith throughout a predetermined arc, the periphery of said rollerbeing in part constituted by a plurality of angularly spaced bars whichare slidable longitudinally in a direction parallel to the axis ofrotation of the roller, a pair of relatively fixed cams at opposite endsof the roller respectively for ensuring that the bars take up apredetermined longitudinal position whilst moving through the arc inwhich they are in frictional contact with the web, means for sensing anydeviation of the web from its required path as it approaches saidroller, and a second pair of cams at opposite ends of the rollerrespectively, said second pair of cams being movable by said means todisplace the bars longitudinally by an amount determined by said meansduring their movement through the arc in which they are not in contactwith the web.

2. Mechanism for correcting any tendency for a moving web to deviatefrom a required path as claimed in claim 1 in which the means forsensing any deviation of the web from its required path comprises a pairof brackets engaging opposite marginal edges of the web, a memberdisplaceable laterally of the web to which the pair of brackets and thesecond pair of cams are connected.

3. Mechanism for correcting any tendency for a moving web to deviatefrom a required path as claimed in claim 2 in which the brackets areadjustable in a direction at right angles to the member to enable thedegree of correction for a given deviation of the web to be varied.

4. Mechanism for correcting any tendency for a mov ing web to deviatefrom a required path as claimed in claim 3 in which portions of theoperative surfaces of 'the' pair of relatively fixed cams areconstituted by the peripheries of rotatable rollersl

1. Mechanism for correcting any tendency for a moving web to deviatefrom a required path comprising in combination a rotatable roller aroundthe periphery of which the web passes so as to be in frictional contacttherewith throughout a predetermined arc, the periphery of said rollerbeing in part constituted by a plurality of angularly spaced bars whichare slidable longitudinally in a direction parallel to the axis ofrotation of the roller, a pair of relatively fixed cams at opposite endsof the roller respectively for ensuring that the bars take up apredetermined longitudinal position whilst moving through the arc inwhich they are in frictional contact with the web, means for sensing anydeviation of the web from its required path as it approaches saidroller, and a second pair of cams at opposite ends of the rollerrespectively, said second pair of cams being movable by said means todisplace the bars longitudinally by an amount determined by said meansduring their movement through the arc in which they are not in contactwith the web.
 2. Mechanism for correcting any tendency for a moving webto deviate from a required path as claimed in claim 1 in which the meansfor sensing any deviation of the web from its required path comprises apair of brackets engaging opposite marginal edges of the web, a memberdisplaceable laterally of the web to which the pair of Brackets and thesecond pair of cams are connected.
 3. Mechanism for correcting anytendency for a moving web to deviate from a required path as claimed inclaim 2 in which the brackets are adjustable in a direction at rightangles to the member to enable the degree of correction for a givendeviation of the web to be varied.
 4. Mechanism for correcting anytendency for a moving web to deviate from a required path as claimed inclaim 3 in which portions of the operative surfaces of the pair ofrelatively fixed cams are constituted by the peripheries of rotatablerollers.